Propeller blade retention ring assembly



Se t. 20, 1955 M. E. cusHMAN PRoPELLER BLADE RETENToN RNG ASSEMBLY Filed Se t.

races are aSSen1bled and the blade iS SecuTed in the pro penefo It vvin be Tea1iZed that the Upsetting operation fol the blade ange is nSuany acconp1iShed vVith the blade hot. Since the fing 36 iS not cTitical in feSpect to hard- 11eSS and iS not Inaterially aected by high tenlperatUreS, the blade llpSetting operation can be accofnplished vvithout dange1 to the heat tfeatInent of the eleITlentS involved- TheTeafter, the haTd Split beaTing raceS 38 and 44 IIlay be aSSeInbled in the c()ld conditionv If an innof beaTing Tace in the foTIn of a conlplete ring weTe S1eeved over the blade shank before upsetting of the fiange Zo elaboTate precautionS vvoUld be necessary to pTotect the Tace fron1 the heat requiTed foI, UpSetting to prevent SofteniI1g of the vefy haTd Tace. Throngh I1Se of the ring 36, Such elaboTate iI1SI11ation becoInes unnecessafy.

CleaTance is allovved betWeen the TingS 36, 3o a]1d 3o and the shankS 4, Z4 and Z4 TeSpectively so that the Tings Inay be readily aSSeInbled befo1e the shank is UpSet and so that they may be readily pasSed downWardly agai11St the ange Zo after the b1ade shank and i1ange have beeI1 Inachined. AlSo, cleafance Inay be a11ovved betWeen the beaTing race 38 and the Shank poftion 24 fo1 inseTtion of a gaSket, of plating, to niniTniZe galling. TTansIniSSion of load fToII1 the blade to the Ting 3o occUTS pTedonlinant1y in the area covered by the f1llet 23. It is prefeTred that the Het radiUS on the Ting 36 be made slightly SmaHer than the fillet TadiuS on the blade Shank.

The blade Tetention arrangeInent heTein deScribed en ables the fabTication and aSSeInbly of a propeHer With nliniInum bulk and weight and th11S posseSSeS advantages over the StTuctuTeS of the priof aTt. The inventioI1 alSo enables eifective otilization of Inultiple-Tow anti-ffiction bearingS to assunle the high centifI1ga1 loading betveen the blade and socket.

ThoIlgh SeveTal en1bodinlents illIlStrating the invention have been Shovvn and deScfibed, it iS to be underStood that the invention Inay be appHed in vaTiouS foTIns. Changes 1Tlay be Inade in the aTrangeTnents, vvithout departing fToIn the spiTit of the invention. IefeTence Should be had to the appended clai1 fo1 defiI1itio1s of the liIT1its of the in vention.

What iS clain1ed iS:

II1 a vaTiable pitch prope11eT a feTrous hub having an 4 integral annulaT blade Socket, including a cylindrical boTe and inteTnal thTeads at the outer end theTeof, a light anoy nonferoUS blade, Said b1ade having a cylindTical butt poftion entering Said hub socket, having an outeT integra1 blade poftion of tTanSveTsely gTeater din1enSion thaI1 the dian1eteT of said butt poItion, and having an integTal an 11Lllaf flange at the inner end of said butt poTtion the iLlnctUfe betWeen said ange and butt poTtion con1ptiSing a curved annular fillet of a Tadi11s SubStantially as gTeat aS the vvidth of said Hange; naInely, SubStantiany equa1 to the dffenoe in Tadius of said ange and butt poftion; 3 one piece contnUouS annL1lar Space Iing of ferrous InateTial Which iS harder and stronger than the blade mateTiaL eIn bfacing Said cyHndTical butt betWeen Said i1ange and Said outeT integfal blade poTtion, Said fing having a1 inside dianeter SobStantiany the Sanle aS and in loose fitting engageolent With Said butt poftion, having a cy1indrical oUte S11rfaco of SUbsfantially the san1e diaIneter aS Said 11ange, having a flat UppeT Sufface noTmal to the blade aXis and having a cUTved lovvel and inner Sufface conlpTiSing a chaInfeTed part coInp1enlentary in shape and in fitting engagenlent Xvith Said ouTved annulaT 1let befWeen the 11ange and but poftion, a longitudinany splif, tvvo-part feTTous innef ball face en1bfacing Said cyHndrica1 butt and having a planar inneT end in tting engagenlent wit11the f1at uppeT SuTface of Said foffous Ting, a longitudinal Split tvvo art onteT fefrous ball Tace eInbTacing said innef face and ed Within said Socket and engaging the cylindrical waH theTeof, beaTng ballS betvveen Said inneT and outer Taces, and nUt n1eanS engaging said Socket thTeadS and the outeT end of said onteT face to secUTe the faces and blade within said hub Socket.

1efeTences cifed in the 1e of thiS patent UNITED STATES PATENTS L9ZL883 I1orgef Ang, 8, 1933 Z,318,485 fIooveT May 4, 1943 Z 499 837 SheetS et aL Mar 7, 1930 FOREIGN PATENTS 303,6Z9 Gfeat Britain Mdy 11, 1939 S19,Z67 Great BTitain Maf. Z0 1940 S64 9Z8 Gfeat BTitain ()ct. 19, 1944 

